Methods and apparatus for use in controlling wireless transceiver operation in a mobile communication device

ABSTRACT

A mobile device operates for communications via a first wireless network with use of a first transceiver. The device performs scanning operations with use of a second transceiver for identifying a set of cell IDs corresponding to a plurality of stations of one or more second wireless networks. The device stores the set of cell IDs in association with an ID of the first wireless network. While operating for communications with use of the second transceiver, the device maintains the first transceiver in a low power state. The device performs scanning operations with use of the second transceiver for identifying a current set of cell IDs, and compares the cell IDs of the current set with cell IDs of the stored set. The device maintains the first transceiver in the low power state or enables its operation based on the comparison.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.non-provisional patent application having application Ser. No.13/560,163 and filing date of Jul. 27, 2012, now U.S. Pat. No.8,483,750, which is a continuation of and claims priority to U.S.non-provisional patent application having application Ser. No.12/612,046 and filing date of Nov. 4, 2009, now U.S. Pat. No. 8,254,985.The content of both of these applications is hereby incorporated byreference herein.

BACKGROUND

1. Technical Field

The present disclosure relates generally to mobile communication devicesadapted to operate for communications in two or more different types ofwireless communication networks, such as wireless wide area networks(WWANs) and wireless local area networks (WWANs) (e.g. operative inaccordance with IEEE 802.11), and more particularly to techniques forcontrolling the operation of wireless transceivers for communications inthese networks, and/or permitting the switching of communicationsbetween such networks.

2. Description of the Related Art

When a mobile communication device is adapted to communicate throughmore than one physical radio domain, the mobile device may select one ofthe domains through which to communicate. This is true for mobiledevices that support operability in both wireless local area networks(WWANs) and wireless wide area networks (WWANs). The WWANs may operatein accordance with IEEE 802.11 standards, and the WWANs may be cellulartelecommunication networks (e.g. operating in accordance with GlobalSystem for Mobile communications “GSM”, General Packet Radio Service“GPRS”, Universal Mobile Telecommunication Systems “UMTS”, etc.).

Cell selection rules in specification documents typically govern cellselection techniques for a mobile device. See, for example, 3^(rd)Generation Partnership Project (3GPP) Technical Specification (TS)45.008, “3^(rd) Generation Partnership Project; Technical SpecificationGroup GSM/EDGE Radio Access Network; Radio subsystem link control”;specifically clause 6.4 “Criteria for cell selection and reselection”and 6.6.2 “Path loss criteria and timings for cell reselection”; forUMTS devices, see e.g. TS 25.304, clause 5.2.

The cell selection technique for GSM specifies a number of monitoredparameters, including a minimum RSSI required to access a candidate celland a minimum amount of time the candidate cell should be the strongestin the list of monitored cells. Per the specification, a candidate cellmay be selected by the mobile device for two different reasons: (1) thepath loss criterion (C1) falls below zero for five (5) seconds (i.e.essentially no signal exists at the receiver), or (2) the calculatedvalue of radio signal strength indicator (RSSI) criterion (C2) isgreater than the C2 of serving cell for more than five (5) seconds.

If the mobile device is adapted to operate with multiple radio accesstechnologies (RAT), the mobile device may operate to autonomously selectbetween WLAN cells and WWAN cells. If cell selection rules similar tothat outlined in the 3GPP specification were utilized for such cellselection, the mobile device might select the WLAN cell if (1) its RSSIexceeds a certain threshold level and (2) the RSSI of the candidate cellis stronger than the current serving cell for greater than some lengthof time (e.g. five or ten seconds). However, the WLAN transceiver of themobile device would need to be operated or enabled often or continuouslyduring operation with the WWAN, which would consume excessive batterypower of the mobile device.

What are needed are improved methods and apparatus for controllingwireless transceiver operations for a mobile device which has multipletransceivers.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the attached figures. Same referencenumerals are used in different figures to denote similar elements.

FIG. 1 is a schematic block diagram illustrating the basic components ofa mobile communication device operating in a wireless communicationsystem which includes a wireless wide area network (WWAN) (e.g. aGSM/GPRS wireless network) and a wireless local area network (WLAN);

FIG. 2 is a schematic diagram of a particular mobile communicationdevice of FIG. 1, namely a mobile station;

FIG. 3A is a flowchart which describes a first method for controllingtransceiver operation of the mobile device, for the switching ofcommunication operations between WWANs and the WLANs;

FIG. 3B is a flowchart which describes a second method for controllingtransceiver operation of the mobile device, for the switching ofcommunication operations between WWANs and the WLANs;

FIG. 4 is a top down view of an environment having the mobile deviceoperating in the wireless communication system and travelling throughcells of WWANs and WLANs, for better illustrating the techniques ofFIGS. 3A and 3B;

FIGS. 5, 6A, and 6B are flowcharts for describing a more detailed methodrelated to the technique of FIG. 3A for controlling transceiveroperation of the mobile device;

FIG. 7 is a map of a geographic region within which the mobile devicemay traverse during its operation, for an illustrative example of FIGS.7-14;

FIG. 8 is a map floor plan of a residence located in the geographicregion of FIG. 7, which includes a WLAN in which the mobile device isadapted to operate; and

FIGS. 9-14 is cell information of the mobile device from WWAN scanningoperations while traversing the geographic region and residence of FIGS.7-8.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Methods and apparatus for use in controlling wireless transceiveroperation in a mobile communication device which is adapted to operatefor communications in a wireless wide area network (WWAN) and a wirelesslocal area network (WLAN) are described herein. In one illustrativeembodiment, the mobile device operates for communications via the WLANwith use of a WLAN transceiver portion. During such operation, themobile device performs one or more scanning operations with use of aWWAN transceiver portion for identifying a set of cell siteidentifications corresponding to a plurality of base stations of one ormore WWANs available in a coverage region of the WLAN. The set of cellsite identifications is stored in association with a WLAN profile of theWLAN. Subsequently, while the mobile device operates for communicationsin a WWAN, the WLAN transceiver portion may be maintained in a low powerstate. During the WWAN operation, the mobile device performs one or morescanning operations with use of the WWAN transceiver portion foridentifying a current set of cell site identifications corresponding tothe currently-serving base station of the WWAN and one or moreneighboring base stations. The mobile device compares cell siteidentifications of the current set with cell site identifications of thestored set, and identifies if the number or percentage of matching cellsite identifications of the current and stored sets meets or exceeds apredetermined threshold. If the predetermined threshold is met orexceeded, the mobile device enables operation of the WLAN transceiverportion for communications via the WLAN; otherwise, the mobile devicerefrains from enabling operation of the WLAN transceiver portion forcommunications via the WLAN. This technique may be performed inassociation with each WLAN profile stored in the mobile device.

In another illustrative embodiment, the mobile device performs one ormore scanning operations with use of the WLAN transceiver portion in ageographical region, but fails to connect with any WLANs in thegeographical region. The mobile device also performs one or morescanning operations with use of the WWAN transceiver portion foridentifying a set of cell site identifications corresponding to aplurality of base stations of one or more WWANs available at its currentlocation. The set of cell site identifications is stored in associationwith an indication of the failure to connect with any WLANs in thegeographic region. Subsequently, while operating for communications viaa WWAN with use of the WWAN transceiver portion, the WLAN transceiverportion may be maintained in a low power state. During the WWANoperation, the mobile device performs one or more scanning operationswith use of the WWAN transceiver portion for identifying a current setof cell site identifications. The current set of cell siteidentifications corresponds to the currently-serving base station of theWWAN and one or more neighboring base stations. The mobile devicecompares cell site identifications of the current set with cell siteidentifications of the stored set. If the mobile device identifies apredetermined condition where the number or percentage of matching cellsite identifications of the current and stored sets meets or exceeds apredetermined threshold, it refrains from enabling operation of its WLANtransceiver portion for communications via a WLAN. This technique may beperformed in association with each one of a plurality of geographicregions (locations) through which the mobile device traverses.

Referring now to the drawings to illustrate one example of the systemenvironment within which the techniques may be practiced, FIG. 1 is aschematic block diagram illustrating the basic components of a mobilecommunication device 102 which operates in a wireless communicationsystem 100. In the example of FIG. 1, mobile device 102 is adapted tocommunicate with a wireless communication network 104 which is acellular telecommunications network (one type of wireless wide areanetwork or “WWAN”). Mobile device 102 is also adapted to communicatewith a wireless local area network “WLAN” 190, which may be an IEEE802.11-based wireless network.

For wireless communication with wireless network 104 (i.e. the WWAN),mobile device 102 utilizes radio frequency (RF) transceiver circuitry108 a and an antenna means 110 a. For wireless communication with WLAN190, mobile device 102 utilizes RF transceiver circuitry 108 b for IEEE802.11-based communications and an antenna means 110 b. With suchconfiguration, mobile device 102 may be referred to as a “dual mode”communication device. Although shown in FIG. 1 as having separate andindependent transceiver components, at least some portions or componentsof these otherwise different transceivers may be shared.

Mobile device 102 may include a visual display 112, a keyboard 114, andperhaps one or more auxiliary user interfaces (UI) 116, each of which iscoupled to a controller 106. Controller 106 is also coupled to RFtransceiver circuitry 108 a and antenna 110 a, as well as RF transceivercircuitry 108 b and antenna 110 b. Typically, controller 106 is embodiedas a central processing unit (CPU) which runs operating system softwarein a memory component (not shown). Controller 106 will normally controloverall operation of mobile device 102, whereas signal-processingoperations associated with communication functions are typicallyexecuted by the RF transceiver circuitry. Controller 106 interfaces withdevice display 112 to display received information, stored information,user inputs, and the like. Keyboard 114, which may be a telephone typekeypad or full alphanumeric keyboard, is normally provided for enteringdata for storage in mobile device 102, information for transmission tonetwork 104, a telephone number to place a telephone call, commands tobe executed on mobile device 102, and possibly other or different userinputs.

Mobile device 102 also includes a battery interface 122 for receivingone or more rechargeable batteries 124. Battery 124 provides electricalpower to electrical circuitry in mobile device 102, and batteryinterface 122 provides for a mechanical and electrical connection forbattery 124. This provides wireless operation and portability of mobiledevice 102. Battery interface 122 is coupled to a regulator 126 whichregulates power to the device.

Mobile device 102 may consist of a single unit, such as a datacommunication device, a cellular telephone, a multiple-functioncommunication device with data and voice communication capabilities, apersonal digital assistant (PDA) enabled for wireless communication, ora computer incorporating an internal modem. Alternatively, mobile device102 may be a multiple-module unit comprising a plurality of separatecomponents, including but in no way limited to a computer or otherdevice connected to a wireless modem. In particular, for example, in themobile terminal block diagram of FIG. 1, the RF transceiver circuitryand antenna may be implemented as a radio modem unit that may beinserted into a port on a laptop computer. In this case, the laptopcomputer would include display 112, keyboard 114, one or more auxiliaryUIs 116, and controller 106 embodied as the computer's CPU. It is alsocontemplated that a computer or other equipment not normally capable ofwireless communication may be adapted to connect to and effectivelyassume control of RF transceiver circuitry 108 a and antenna 110 a of asingle-unit device such as one of those described above. Such a mobiledevice 102 may have a more particular implementation as described laterin relation to mobile station 202 of FIG. 2.

Mobile device 102 sends communication signals to and receivescommunication signals over wireless communication links. For example,mobile device 102 may communicate with wireless network 104 via antenna110 a. RF transceiver circuitry 108 a performs functions similar tothose of a base station controller 140, including for examplemodulation/demodulation and possibly encoding/decoding andencryption/decryption. It is also contemplated that RF transceivercircuitry 108 a may perform certain functions in addition to thoseperformed by base station controller 140.

In the embodiment shown in FIG. 1, wireless network 104 technology isconfigured in accordance with Global Systems for Mobile communications(GSM) and General Packet Radio Service (GPRS) standards. Such networkmay further operate in accordance with Enhanced Data rates for GSMEvolution (EDGE) or Enhanced GPRS (EGPRS). Note, however, wirelessnetwork 104 may be based on any other suitable network technology, suchas a Long-Term Evolution (LTE)-based network, an EVolution-Data Only(EV-DO)-based network, a UMTS-based network, or High Speed Packet Access(HSPA), as examples. It will be apparent to those skilled in art thatthe RF transceiver circuitry will be adapted to particular wirelessnetwork or networks in which mobile device 102 is intended to operate.

In the example embodiment of FIG. 1, wireless network 104 includes abase station controller (BSC) 140 with a base station 142, a MobileSwitching Center (MSC) 134, a Home Location Register (HLR) 132, aServing GPRS Support Node (SGSN) 138, and a Gateway GPRS Support Node(GGSN) 136. MSC 134 is coupled to BSC 140 and to a landline network 128,such as a Public Switched Telephone Network (PSTN). SGSN 138 is coupledto BSC 140 and to GGSN 136, which is in turn coupled to a public orprivate data network 130 (such as the Internet). HLR 132 is coupled toMSC 134, SGSN 138, and GGSN 136. Mobile device 102 also operates using amemory module 120, such as a Subscriber Identity Module (SIM) (or e.g. aUniversal SIM or U-SIM, or a Removable User Identity Module or R-UIM),which is connected to or inserted in mobile device 102 at an interface118.

Base station 142 may be a fixed transceiver station, and BSC 140 andbase station 142 may together be referred to as fixed transceiverequipment. The fixed transceiver equipment provides wireless networkcoverage for a particular coverage area commonly referred to as a“cell”. The transceiver equipment transmits communication signals to andreceives communication signals from mobile terminals within its cell viabase station 142. The transceiver equipment normally performs suchfunctions as modulation and possibly encoding and/or encryption ofsignals to be transmitted to the mobile terminal in accordance withparticular, usually predetermined, communication protocols andparameters, under control of its controller. The transceiver equipmentsimilarly demodulates and possibly decodes and decrypts, if necessary,any communication signals received from mobile device 102 within itscell. Communication protocols and parameters may vary between differentnetworks. For example, one network may employ a different modulationscheme and operate at different frequencies than other networks.

Again, WLAN 190 may be an IEEE 802.11-based wireless network whichprovides communications for mobile device 102 in accordance with IEEE802.11 standards. Although the present embodiment relates to a WLAN ofthe IEEE 802.11 type and a WWAN of the cellular network type, anysuitable wireless network technologies may be utilized, such as WiMAXtechnologies (e.g. IEEE 802.16e-based technologies). For example, theWLAN may be an IEEE 802.11-based network and the WWAN may be an IEEE802.16e-based network. As another example, the WLAN may be an IEEE802.16e-based network and the WWAN may be the cellular network.

Referring now to FIG. 2, electrical components of one preferred mobiledevice 202 (e.g. a mobile station or terminal) will be described. Mobiledevice 202 is adapted to operate in connection with differentcommunications systems which may be referred to as WLAN and WWAN).Mobile device 202 may be a two-way mobile communication device having atleast voice and advanced data communication capabilities, which mayinclude the capability to communicate with other computer systems.Depending on the functionality provided by mobile device 202, it may bereferred to as a data messaging device, a two-way pager, a cellulartelephone with data messaging capabilities, a wireless Internetappliance, or a data communication device (with or without telephonycapabilities). As mobile device 202 is a portable battery-powereddevice, it also includes a battery interface 254 for receiving one ormore rechargeable batteries 256. Such a battery 256 provides electricalpower to most if not all electrical circuitry in mobile device 202, andbattery interface 254 provides for a mechanical and electricalconnection for it. Battery interface 254 is coupled to a regulator (notshown in FIG. 2) that provides a regulated voltage V to all of thecircuitry.

As described, mobile device 202 is adapted to wirelessly communicatewith WLANs, such as WLAN 190. In addition, mobile device 202 may beadapted to wirelessly communicate with cellular base station transceiversystems 200 of various WWANs, including systems 142, 282, and 284. Forcommunication with cellular networks, mobile device 202 utilizescommunication subsystem 211. For communication with WLANs, mobile device202 utilizes an additional communication subsystem 291 which may havesimilar structural components as communication subsystem 211. With suchconfiguration, mobile device 202 may be referred to as a “dual mode”mobile station. Although shown in FIG. 2 as having separate andindependent subsystems, at least some portions or components of theseotherwise different subsystems may be shared.

For communications with the WWAN, communication subsystem 211 includes areceiver 212, a transmitter 214, and associated components, such as oneor more antenna elements 216 and 218 (e.g. embedded or internal), localoscillators (LOs) 213, and a processing module such as a digital signalprocessor (DSP) 220. Communication subsystem 211 is analogous to RFtransceiver circuitry 108 a and antenna 110 a shown in FIG. 1. As willbe apparent to those skilled in the art, particular design ofcommunication subsystem 211 depends on the communication network inwhich mobile device 202 is intended to operate.

Network access is associated with a subscriber or user of mobile device202, and therefore mobile device 202 requires a memory module 262, suchas a Subscriber Identity Module or “SIM” card, a Universal SIM (U-SIM),or a Removable User Identity Module (R-UIM), to be inserted in orconnected to an interface 264 of mobile device 202 in order to operatein the network. After network procedures have been completed, mobiledevice 202 may send and receive communication signals through thenetwork. Signals received by antenna 216 through the network are inputto receiver 212, which may perform such common receiver functions assignal amplification, frequency down conversion, filtering, channelselection, and the like, and in example shown in FIG. 2,analog-to-digital (A/D) conversion. A/D conversion of a received signalallows more complex communication functions such as demodulation anddecoding to be performed in DSP 220. In a similar manner, signals to betransmitted are processed, including modulation and encoding, forexample, by DSP 220. These DSP-processed signals are input totransmitter 214 for digital-to-analog (D/A) conversion, frequency upconversion, filtering, amplification and transmission over communicationnetwork via antenna 218. DSP 220 not only processes communicationsignals, but also provides for receiver and transmitter control. Forexample, the gains applied to communication signals in receiver 212 andtransmitter 214 may be adaptively controlled through automatic gaincontrol algorithms implemented in DSP 220.

For communications with WLAN 190, communication subsystem 291 mayinclude modules and processes which operate in accordance with IEEE802.11 for communications. Communication subsystem 291 may be or includewhat is referred to as a WLAN driver, with which microprocessor 238 maycommunicate and control. Communication subsystem 291 may have similarstructural components as communication subsystem 211, such as areceiver, a transmitter, and associated components, such as one or more(e.g. embedded or internal) antenna elements, local oscillators (LOs),and a processing module such as a baseband (BB) and media access control(MAC) processing module. As will be apparent to those skilled in thefield of communications, the particular design of communicationsubsystem 291 depends on the communication network in which mobiledevice 202 is intended to operate. Again, in the present disclosure,communication subsystem 291 (including its associatedprocessor/processing components) are operative in accordance with IEEE802.11 standards.

Mobile device 202 may send and receive communication signals throughWLAN 190 after required network procedures have been completed. Signalsreceived by its antenna means via the network are input to the receiver,which may perform such common receiver functions as signalamplification, frequency down conversion, filtering, channel selection,and like, including A/D conversion. A/D conversion of a received signalallows more complex communication functions such as demodulation anddecoding to be performed in the BB/MAC processing module ofcommunication subsystem 291. In a similar manner, signals to betransmitted are processed, including modulation and encoding, forexample, by the BB/MAC processing module. These processed signals areinput to the transmitter for D/A conversion, frequency up conversion,filtering, amplification and transmission through the network via theantenna means. The BB/MAC processing module not only processescommunication signals, but may also provide for receiver and transmittercontrol. Note that the receiver and transmitter may share one or moreantennas through an antenna switch, instead of having two separatededicated antennas.

Mobile device 202 includes a microprocessor 238 that controls overalloperation of mobile device 202. This control includes the processingtechniques of the present disclosure, which may also utilize the BB/MACprocessing module of communication subsystem 291 and/or DSP 220 if andas needed. Communication functions, including at least data and voicecommunications, are performed by communication subsystem 211 andsubsystem 291 as described above. Microprocessor 238 also interacts withadditional device subsystems such as a display 222, a flash memory 224,a random access memory (RAM) 226, auxiliary input/output (I/O)subsystems 228, a serial port 230, a keyboard 232, a speaker 234, amicrophone 236, a short-range communications subsystem 240, and anyother device subsystems generally designated at 242. As apparent, someof these subsystems shown in FIG. 2 perform communication-relatedfunctions, whereas other subsystems may provide “resident” or on-devicefunctions. Notably, some subsystems, such as keyboard 232 and display222, for example, may be used for both communication-related functions,such as entering a text message for transmission over a communicationnetwork, and device-resident functions such as a calculator or tasklist. Operating system software used by microprocessor 238 may be storedin a persistent store such as flash memory 224, which may alternativelybe a read-only memory (ROM) or similar storage element (not shown).Those skilled in the art will appreciate that the operating system,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store such as RAM 226.

Microprocessor 238, in addition to its operating system functions, mayenable execution of software applications on mobile device 202. Apredetermined set of applications that control basic device operations,including at least data and voice communication applications, willnormally be installed on mobile device 202 during its manufacture. Oneapplication that may be loaded onto mobile device 202 may be a personalinformation manager (PIM) application having the ability to organize andmanage data items relating to the user such as, but not limited to,e-mail, calendar events, voice mails, appointments, and task items.Naturally, one or more memory stores are available on mobile device 202and SIM 256 to facilitate storage of PIM data items and otherinformation.

The PIM application may have the ability to send and receive data itemsvia the wireless network. In one embodiment, PIM data items areseamlessly integrated, synchronized, and updated via the wirelessnetwork, with the wireless device user's corresponding data items storedand/or associated with a host computer system thereby creating amirrored host computer on mobile device 202 with respect to such items.This is especially advantageous where the host computer system is thewireless device user's office computer system. Additional applicationsmay also be loaded onto mobile device 202 through network, an auxiliaryI/O subsystem 228, serial port 230, short-range communications subsystem240, or any other suitable subsystem 242, and installed by a user in RAM226 or a non-volatile store (not shown) for execution by microprocessor238. Such flexibility in application installation increases thefunctionality of mobile device 202 and may provide enhanced on-devicefunctions, communication-related functions, or both. For example, securecommunication applications may enable electronic commerce functions andother such financial transactions to be performed using mobile device202.

In a data communication mode, a received signal such as a text message,an e-mail message, or web page download will be processed bycommunication subsystem 211 and input to microprocessor 238.Microprocessor 238 may further process the signal for output to display222 or alternatively to auxiliary I/O device 228. A user of mobiledevice 202 may also compose data items, such as e-mail messages, forexample, using keyboard 232 in conjunction with display 222 and possiblyauxiliary I/O device 228. Keyboard 232 may be a complete alphanumerickeyboard and/or telephone-type keypad. These composed items may betransmitted over a communication network through communication subsystem211 or 291. For voice communications, the overall operation of mobiledevice 202 is substantially similar, except that the received signalswould be output to speaker 234 and signals for transmission would begenerated by microphone 236. Alternative voice or audio I/O subsystems,such as a voice message recording subsystem, may also be implemented onmobile device 202. Although voice or audio signal output may beaccomplished primarily through speaker 234, display 222 may also be usedto provide an indication of the identity of a calling party, duration ofa voice call, or other voice call related information, as some examples.

Serial port 230 in FIG. 2 is normally implemented in a personal digitalassistant (PDA)-type communication device for which synchronization witha user's desktop computer is a desirable, albeit optional, component.Serial port 230 enables a user to set preferences through an externaldevice or software application and extends the capabilities of mobiledevice 202 by providing for information or software downloads to mobiledevice 202 other than through a wireless network. The alternate downloadpath may, for example, be used to load an encryption key onto mobiledevice 202 through a direct and thus reliable and trusted connection tothereby provide secure device communication. Short-range communicationssubsystem 240 of FIG. 2 is an additional optional component thatprovides for communication between mobile device 202 and differentsystems or devices, which need not necessarily be similar devices. Forexample, subsystem 240 may include an infrared device and associatedcircuits and components, or a Bluetooth™ communication module to providefor communication with similarly enabled systems and devices. Bluetooth™is a registered trademark of Bluetooth SIG, Inc.

Again, although FIGS. 1-2 focus on the use of two specific types ofnetworks (namely a cellular network as the WWAN and an IEEE 802.11network as the WLAN), any two suitable networks may be utilized, whereone of the networks has overlapping coverage with or is contained withinthe other network (e.g. WiMAX or IEEE 802.16, Home Node-B cells of a 3Gmacro Radio Access Network (RAN), or BLUETOOTH™, etc.).

FIG. 3A is a flowchart for describing a technique for use by a mobilecommunication device in controlling operation of its transceivers forthe selection of wireless networks. The mobile communication device maybe that which has been shown and described earlier in relation to FIG. 1or 2, making use of one or more controllers or processors (e.g.microprocessor) to perform the techniques. The mobile device has a WWANtransceiver portion (e.g. RF transceiver circuitry 108 a of FIG. 1, orcommunication subsystem 211 of FIG. 2) and a WLAN transceiver portion(e.g. RF transceiver circuitry 108 b of FIG. 1, or communicationsubsystem 291 of FIG. 2) for operation. The technique may be embodied asa computer program product which includes a computer readable medium(e.g. memory of computer disk) and computer instructions stored in thecomputer readable medium. The computer instructions are executable bythe one or more controllers or processors and adapted in accordance withthe described steps or logic.

The mobile device has one or more WLAN profiles stored in its memory.Each WLAN profile has WLAN information contained therein. The WLANinformation may include an identification which identifies the WLAN(e.g. a SSID or ESSID) and authentication information for obtainingaccess to the WLAN (e.g. a network key, passkey, security key, etc.).When operating in a WLAN, the mobile device normally operates forcommunications in one or more WLANs corresponding to its one or morestored WLAN profiles. On the other hand, the mobile device normallyrefrains from operating for communications with WLANs other than thoseWLANs having stored WLAN profiles. However, a user of the mobile devicemay manually instruct, via the user interface, the mobile device tooperate with these other WLANs, where a new WLAN profile for the WLANmay be created and stored in the memory.

Beginning at a start block 302 of FIG. 3A, the mobile device operatesfor communications via a WLAN with use of the WLAN transceiver portion(step 304 of FIG. 3A). The connection between the mobile device and theWLAN is established via a wireless access point (AP) of the WLAN withuse of the WLAN identification and authentication information containedin the WLAN profile. While operating in the WLAN, the mobile devicereceives services made available in the WLAN. The services may be orinclude a voice telephony service (e.g. VoIP) and/or a datacommunication service (e.g. Web browsing service, data synchronizationservice, e-mail message delivery service, etc., facilitated via a packetdata communication service).

During this time, the mobile device may maintain its WWAN transceiverportion in a low power state. The low power state may be characterizedby powering off the WWAN transceiver portion, in whole or in part. Inanother embodiment, the WWAN transceiver portion is maintained in itsnormal powered state (i.e. not the low power state) and operating duringthis time. In yet another embodiment, the mobile device receives partialservices via the WWAN (e.g. voice call service, without packet dataservice) and partial services from the WLAN (e.g. packet data services).

In any event, while operating in the WLAN, the mobile device may performoperations with use of its WWAN transceiver portion either regularly(e.g. periodically, with use of a periodic timer-based trigger) or inresponse to detecting a predetermined condition (e.g. detecting a changein location, or an increase in mobility, etc.). The WWAN operations atthis time include scanning operations with use of the WWAN transceiverportion (step 306 of FIG. 3A). In the scanning operation, the mobiledevice receives, via its WWAN transceiver portion, a set of cell siteidentifications corresponding to a plurality of base stations of one ormore WWANs available at its current location. These cell siteidentifications may be or be referred to as cell IDs. As apparent, thecurrent location of the mobile device is a location at which the WLAN isalso available. The mobile device then stores, in its memory, the set ofcell site identifications in association with the WLAN profile of theWLAN (step 308 of FIG. 3A). The mobile device may then place the WWANtransceiver portion into the low power state, if desired.

Sometime later, the mobile device has no connection to the WLAN butoperates for communications in a WWAN (step 310 of FIG. 3A). The mobiledevice has selected the particular WWAN from other WWANs based onnetwork selection techniques known in the art; the connection betweenthe mobile device and the WWAN is established via a currently-servingbase station of the WWAN. While operating in the WWAN, the mobile devicereceives services made available in the WWAN. The services may be orinclude a voice telephony service and/or a data communication service(e.g. Web browsing service, data synchronization service, e-mail messagedelivery service, etc., facilitated via a packet data communicationservice).

During this time, the mobile device may set and maintain its WLANtransceiver portion in a low power state (step 312 of FIG. 3A). The lowpower state of the WLAN transceiver portion may be characterized bypowering off the WLAN transceiver portion, in whole or in part. On theother hand, the low power state may be characterized by the setting of asubstantially reduced scan rate of the WLAN transceiver portion. Inanother embodiment, the WLAN transceiver portion is maintained in itsnormal powered state (i.e. not the low power state) and operatingwithout the receipt of services. In any event, while operating in theWWAN, the mobile device performs the following operations to identifywhether it should enable its WLAN transceiver portion forcommunications. In particular, the mobile device performs a scanningoperation with use of the WWAN transceiver portion (step 314 of FIG.3A). During the scanning operation, the mobile device receives a currentset of cell site identifications via its WWAN transceiver portion. Thecurrent set of cell site identifications are received from andcorrespond to the currently-serving base station and one or moreneighboring base stations of the mobile device.

The mobile device then compares cell site identifications of the currentset with cell site identifications of the previously-stored setassociated with the WLAN profile (step 316 of FIG. 3A). The mobiledevice identifies, based on this comparison, whether the number orpercentage of matching cell site identifications of the current andstored sets meets or exceeds a predetermined threshold (step 318 of FIG.3A). In response to identifying that the predetermined threshold isexceeded, the mobile device causes the WLAN transceiver portion to exitthe low power state and enables operation of the WLAN transceiverportion for communications via the WLAN (step 320 of FIG. 3A).Otherwise, if the predetermined threshold is not exceeded, the mobiledevice may maintain the WLAN transceiver portion in the low power state,and/or refrain from enabling operation of the WLAN transceiver portionfor communications via the WLAN.

In step 320 of FIG. 3A, the mobile device performs a scanning operationusing the WLAN transceiver portion for identifying whether the WLANassociated with the WLAN profile is available. If the WLAN is available,a connection may be established between the mobile device and the WLANvia a wireless access point (AP) of the WLAN (step 322 of FIG. 3A). Theconnection may be established with use of the WLAN identification andauthentication information contained in the WLAN profile. If yes in step322, steps of the flowchart are repeated starting at step 304, where themobile device again operates with and receives the services madeavailable in the WLAN. Steps 306 and 308 may also be performed again,where the set of cell site identifications associated with the WLANprofile are updated, for adding any additionally received cell siteidentifications that are not already included in the stored set of cellsite identifications associated with the WLAN profile.

If no connection is established with the WLAN (e.g. the WLAN isunavailable, or there is a communication error) in step 322, however,the mobile device continues to operate and receive the (e.g. full)services in the WWAN. Steps of the flowchart are repeated starting atstep 310, where the WLAN transceiver portion is placed back in the lowpower state in step 312.

Note that steps 304-308 of FIG. 3A may be performed for each WLAN withwhich the mobile device connects and maintains a WLAN profile.Relatedly, steps 316 and 318 of FIG. 3A may be performed with respect toeach stored WLAN profile in the mobile device. Here, the mobile devicecompares the current set of cell site identifications with eachdifferent stored set of cell site identifications associated with eachdifferent WLAN profile. If any one of the comparisons results in meetingor exceeding the predetermined threshold, the mobile device causes theWLAN transceiver portion to exit the low power state for scanning instep 320.

In one embodiment, the storing of the set of cell site identificationsassociated with the WLAN profile in steps 306 and 308 is performed onlya single time when (e.g. initially) connected with the correspondingWLAN. In another embodiment, the mobile device regularly updates thestored set of cell site identifications during operation. In that case,steps 306 and 308 are repeated for the same WLAN, for adding anyadditionally-received cell site identifications that do not alreadyexist in the stored set associated with the WLAN profile. Such atechnique is useful especially in the case where the coverage region ofthe WLAN is relatively large and overlaps with several different cellsof one or more WWANs (which may be the case when the WLAN has aplurality of wireless APs).

FIG. 3B is a flowchart for describing an alternative technique for useby a mobile communication device in controlling operation of itstransceivers for the selection of wireless networks. The mobilecommunication device may be that which has been shown and describedearlier in relation to FIG. 1 or 2, making use of one or morecontrollers or processors (e.g. microprocessor) to perform thetechniques. The technique may be embodied as a computer program productwhich includes a computer readable medium (e.g. memory of computer disk)and computer instructions stored in the computer readable medium. Thecomputer instructions are executable by the one or more controllers orprocessors and adapted in accordance with the described steps or logic.

As described earlier above, the mobile device has one or more WLANprofiles stored in its memory. Each WLAN profile has WLAN informationcontained therein. The WLAN information may include an identificationwhich identifies the WLAN (e.g. a SSID or ESSID) and authenticationinformation for obtaining access to the WLAN (e.g. a network key,passkey, security key, etc.). The mobile device normally operates forcommunications in one or more WLANs corresponding to the one or morestored WLAN profiles. On the other hand, the mobile device normallyrefrains from operating for communications with WLANs other than thoseWLANs having stored WLAN profiles. However, a user of the mobile devicemay manually instruct, via the user interface, the mobile device tooperate with these other WLANs, where a new WLAN profile for the WLANmay be created and stored in the memory.

Beginning at a start block 302 of FIG. 3B, the mobile device performsone or more scanning operations using the WLAN transceiver portion (step354 of FIG. 3B). The mobile device performs the scanning operations inorder to identify whether any WLAN associated with any one of its storedWLAN profiles is available. The scanning operations may be active orpassive scanning operations. If one of the WLANs is available, aconnection between the mobile device and the WLAN may be established viaa wireless AP of the WLAN. The scanning operation and the establishmentof the connection are performed with use of the WLAN identification andauthentication information contained in the WLAN profile.

If the connection with the WLAN is established in step 356, the mobiledevice operates for communications via the WLAN with use of the WLANtransceiver portion (step 358 of FIG. 3B). While operating in the WLAN,the mobile device receives services made available in the WLAN. Theservices may be or include a voice telephony service (e.g. VoIP) and/ora data communication service (e.g. Web browsing service, datasynchronization service, e-mail message delivery service, etc.,facilitated via a packet data communication service).

During this time, the mobile device may maintain its WWAN transceiverportion in a low power state. The low power state may be characterizedby powering off the WWAN transceiver portion, in whole or in part. Inanother embodiment, the WWAN transceiver portion is maintained in itsnormal powered state (i.e. not the low power state) and operating duringthis time. In yet another embodiment, the mobile device receives partialservices via the WWAN (e.g. voice call service, without packet dataservice) and partial services from the WLAN (e.g. packet data services)during this time.

If, in step 356, no connection is established with any WLANcorresponding to any one of the stored WLAN profiles, the mobile devicewill perform operations with use of its WWAN transceiver portion. Theseoperations include the performing a scanning operation with use of theWWAN transceiver portion (step 360 of FIG. 3B). During the scanningoperation, the mobile device receives, via its WWAN transceiver portion,a set of cell site identifications corresponding to a plurality of basestations of one or more WWANs available at its current location. Thesecell site identifications may be or be referred to as cell IDs. Here,the current location of the mobile device is a location at which noWLANs of the stored WLAN profiles are available. Note that private WLANsthat are not accessible to the mobile device might exist at itslocation. The mobile device then stores, in its memory, the set of cellsite identifications in association with a WLAN failure indication (step362 of FIG. 3B), or in any other fashion to designate that the setcorresponds to no WLAN connection. The set of cell site identifiers isalso stored in association with a location identification, whichdistinguishes between the set and other stored sets of cell siteidentifiers.

Sometime later, the mobile device has no connection to the WLAN butoperates for communications in a WWAN (step 364 of FIG. 3B). The mobiledevice has selected the particular WWAN from other WWANs based onnetwork selection techniques known in the art; the connection betweenthe mobile device and the WWAN is established via a currently-servingbase station of the WWAN. While operating in the WWAN, the mobile devicereceives services made available in the WWAN. The services may be orinclude a voice telephony service and/or a data communication service(e.g. Web browsing service, data synchronization service, e-mail messagedelivery service, etc., facilitated via a packet data communicationservice).

During this time, the mobile device normally sets and maintains its WLANtransceiver portion in a low power state (step 366 of FIG. 3B). Again,the low power state of the WLAN transceiver portion may be characterizedby powering off the WLAN transceiver portion, in whole or in part. Onthe other hand, the low power state may be characterized by the settingof a substantially reduced scan rate of the WLAN transceiver portion. Inanother embodiment, the WLAN transceiver portion is maintained in itsnormal powered state (i.e. not the low power state) and operatingwithout the receipt of services.

In any event, while operating in the WWAN, the mobile device performsthe following operations to identify whether it should enable its WLANtransceiver portion for communications. The mobile device performs theseoperations either regularly (e.g. periodically, with use of a periodictimer-based trigger) or in response to detecting a predeterminedcondition (e.g. detecting a change in location, or an increase inmobility, etc.). In particular, the mobile device performs a scanningoperation with use of the WWAN transceiver portion (step 368 of FIG.3B). During the scanning operation, the mobile device receives a currentset of cell site identifications via its WWAN transceiver portion. Thecurrent set of cell site identifications are received from andcorrespond to the currently-serving base station and one or moreneighboring base stations available at the current location of themobile device. The mobile device then compares cell site identificationsof the current set with cell site identifications of the stored setassociated with the WLAN profile (step 370 of FIG. 3B). The mobiledevice identifies, based on this comparison, whether the number orpercentage of matching cell site identifications of the current andstored sets meets or exceeds a predetermined threshold (step 372 of FIG.3B).

In response to identifying that the predetermined threshold is notexceeded in step 372, the mobile device causes the WLAN transceiverportion to exit the low power state and enables operation of the WLANtransceiver portion for communications via the WLAN (step 374 of FIG.3B). Otherwise, if the predetermined threshold is exceeded in step 372,the mobile device repeats the steps in the flowchart for operating inthe WWAN (step 364) and maintaining the WLAN transceiver portion in thelow power state (step 366), and/or refrain from enabling operation ofthe WLAN transceiver portion for communications via the WLAN.

In step 374 of FIG. 3B, repeating back to step 354, the mobile deviceperforms a scanning operation using the WLAN transceiver portion foridentifying whether any WLAN associated with any one of the stored WLANprofiles is available at its current location. If a WLAN is available, aconnection may be established between the mobile device and the WLAN viaa wireless AP of the WLAN. If a connection is established in step 356,the mobile device operates with and receives the services made availablein the WLAN. If no connection is established in step 356, then thesubsequent steps are performed again as previously described.

The set of cell site identifications associated with the WLAN profilemay be updated in steps 360 and 362, for adding any additionallyreceived cell site identifications that are not already included in thestored set of cell site identifications associated with the WLAN failureindication and location identifier. The mobile device continues tooperate and receive services in the WWAN in step 364, where the WLANtransceiver portion may be placed back in the low power state in step366.

In another embodiment, step 374 may alternatively merely provide anindication that WLAN scanning is permissible, but WLAN scanning willoccur only if other conditions or indications are met as well. Forexample, step 374 may indicate that the enabling of the WLAN transceiverand the WLAN scanning is permissible, but the enabling and scanning willonly occur if and when a timer-triggered WLAN scanning process alsoindicates that it is time for WLAN scanning to occur (e.g. timerexpiration or interrupt). If such a technique is employed, even thoughthe timer-triggered WLAN scanning process indicates that it is time forWLAN scanning to occur, the enabling and scanning may be restrictedindefinitely if the mobile device remains in a coverage region where thepredetermined threshold is regularly exceeded (i.e. “YES” in step 372).In yet another embodiment, a time-triggered WLAN scanning process isutilized by the mobile device, but step 374 serves to increase the scanrate (i.e. decrease the initial value of the timer when set) of thetime-triggered WLAN scanning process from the current scan rate.

Note further that steps 360 and 362 of FIG. 3B may be performed for eachdifferent location for which no WLAN connection was made. Relatedly,steps 370 and 372 of FIG. 3B may be performed with respect to eachdifferent set of cell site identifications corresponding to eachdifferent location identifier. Here, the mobile device compares thecurrent set of cell site identifications with each different stored setof cell site identifications associated with each different locationidentifier. If all of the comparisons result in a failure to meet orexceed the predetermined threshold, the mobile device causes the WLANtransceiver portion to exit the low power state for scanning in step374.

In one embodiment, the storing of the set of cell site identificationsassociated with the location identifier in steps 360 and 362 isperformed only a single time when (e.g. initially) there is no WLANconnection made. In another embodiment, the mobile device regularlyupdates the stored set of cell site identifications during operation. Inthat case, steps 360 and 362 are repeated for the same coverage region,for adding any additionally-received cell site identifications that donot already exist in the stored set associated with the locationidentifier.

Note that step 320 (FIG. 3A) or step 374 (FIG. 3B) may merely provide orindicate a permission or allowance to operate the WLAN transceiverportion. If mobile device 202 operates in an automatic network selectionmode, for example, then it may automatically (i.e. without userintervention) switch operation for communications with the WLAN. Ifmobile device 202 operates in a manual network selection mode, then itmay automatically (i.e. without user intervention) cause an indicatorwhich indicates the availability of the WLAN to be visually display inits visual display and optionally provide an audible alert. This userinterface mechanism is provided to alert the end user of mobile device202 to decide whether or not to select (i.e. switch to) thenewly-available and permitted WLAN. In response to an end-user actuationof an input switch of the user interface of mobile device 202,indicating a manual selection of the WLAN, mobile device 202 switchesoperation for communications to the WLAN. In an alternative approach,the indicator is provided for manual selection for a predetermined timeperiod, however the mobile device 202 will automatically switchoperation for communications with the WLAN unless the end user indicatesa preference not to switch to it within the predetermined time period.When switching is performed (whether automatic or manual or other),mobile device 202 operates to switch use of its appropriate radio or RFtransceiver portions corresponding to the appropriate wirelesscommunication network.

Advantageously, since the WLAN transceiver portion need not becontinuously enabled or activated, power consumption is reduced andbattery life is increased with use of the described techniques. In oneembodiment, mobile device 202 utilizes both techniques of FIGS. 3A and3B in combination to further reduce power consumption.

To help further illustrate the techniques of the present disclosure,FIG. 4 is a top down view of a geographic region having one or moreWWANs which provide a plurality of WWAN cells 412, 414, 418, 420, 422,and 424 of communication coverage, and one or more WLANs which provide aplurality of WLAN cells 406 and 408 of communication coverage. As shownin the top down view, many of the cells provide overlappingcommunication coverage where so depicted. This cell configuration shownhas been provided for illustrative purposes, and will vary in practiceas one skilled in the art will appreciate.

FIG. 4 will first be described to illustrate the technique associatedwith the flowchart of FIG. 3A. A first WLAN includes a wireless AP 404which defines a coverage region or WLAN cell 406 and a second WLANincludes a wireless AP 450 which defines a coverage region or WLAN cell408. The first WLAN having wireless AP 404 has an identification whichis a set service identifier (SSID). In this example, the SSID of thefirst WLAN is “ABC123.”

Mobile device 202 has a plurality of WLAN profiles stored in its memory,including a WLAN profile associated with the first WLAN having wirelessAP 404. The stored WLAN profile for the first WLAN includes the SSID of“ABC123” and unique authentication information associated therewith. Aset of WWAN cell identifications is also stored in association with thisWLAN profile. In this example, the set of WWAN cell identificationsincludes WWAN cell identifications (e.g. cell IDs), which correspond toWWAN cells 410, 412, 414, 416, and 418. Mobile device 202 does not haveany stored WLAN profile or information for the second WLAN havingwireless AP 450.

In FIG. 4, mobile device 202 is shown to traverse a path through thevarious cells of communication coverage. Mobile device 202 is initiallyoperating in a WWAN and has its WLAN transceiver portion in the lowpower state. When performing a WWAN scanning operation in a location J,mobile device 202 receives a current set of cell IDs corresponding toWWAN cells 416 and 418. The comparison between the current and storedsets of cell IDs results in a match of two cell IDs (WWAN cells 416 and418) out of the five cell IDs (WWAN cells 410, 412, 414, 416, and 418),which is a 40% match. In this example, the predetermined threshold forWLAN operation is set at three (3) cell IDs or 60% (i.e. 3 out of 5). As40% does not meet or exceed the predetermined threshold of 60%, themobile device refrains from enabling its WLAN transceiver portion andmaintains communications with the WWAN.

Subsequently, moving to a location K, mobile device 202 continues tooperate in the WWAN with its WLAN transceiver portion in the low powerstate. When performing a WWAN scanning operation in the location K,mobile device 202 receives a current set of cell IDs corresponding toWWAN cells 410, 412, 416, and 418. The comparison between the currentand stored sets of cell IDs results in a match of three cell IDs (WWANcells 410, 416, and 418) out of the five cell IDs (WWAN cells 410, 412,414, 416, and 418), which is a 60% match. As 60% meets the predeterminedthreshold of 60%, there is an increased probability that the WLAN willbe found. In response, the mobile device enables its WLAN transceiverportion and performs a scanning operation with a selected scanningprofile in attempt to identify the first WLAN corresponding to itsstored WLAN profile. In this case, mobile device 202 is not locatedwithin the coverage region of wireless AP 404 of the first WLAN, andtherefore is unable to connect. Mobile device 202 continues to operatein the WWAN, but may regularly perform scanning operations using itsWLAN transceiver portion in attempt to identify the first WLAN.

Later, moving to a location L, mobile device 202 performs a WWANscanning operation and receives a current set of cell IDs correspondingto WWAN cells 410, 412, and 418. The comparison between the current andstored sets of cell IDs again results in a match of three cell IDs (WWANcells 410, 412, and 418) out of the five cell IDs (WWAN cells 410, 412,414, 416, and 418), which is a 60% match. As 60% meets the predeterminedthreshold of 60%, the mobile device enables its WLAN transceiver portionand performs a scanning operation in attempt to identify the first WLANcorresponding to its stored WLAN profile. In this case, mobile device202 is located within the coverage region of wireless AP 404 of thefirst WLAN, and therefore is able to connect in the WLAN. Thus, themobile device 202 operates for communications in the first WLAN. Inaddition, the mobile device 202 may place its WWAN transceiver portionin the low power state if desired, or request and receive only partialservices from the WWAN (e.g. the remaining services being obtaining viathe first WLAN).

Subsequently, moving to a location M, mobile device 202 loses coveragewith the first WLAN and switches operation to the WWAN in response. Whenperforming a WWAN scanning operation in the location M, mobile device202 receives a current set of cell IDs corresponding to WWAN cells 410,414, and 424. The comparison between the current and stored sets of cellIDs results in a match of two cell IDs (WWAN cells 410 and 414) out ofthe five cell IDs (WWAN cells 410, 412, 414, 416, and 418), which is a40% match. As 40% does not meet or exceed the predetermined threshold of60%, the mobile device refrains from enabling its WLAN transceiverportion and maintains communications with the WWAN.

Moving to a location N, mobile device 202 receives a current set of cellIDs corresponding to WWAN cells 420, 422, and 424, resulting in a matchof zero cell IDs or 0% match. Thus, mobile device 202 maintains the lowpower state of its WLAN transceiver portion. At a location P, mobiledevice 202 receives a current set of cell IDs corresponding to WWANcells 414, 422 and 424, resulting in a 20% match of one cell ID (WWANcell 414) out of the five cell IDs (WWAN cells 410, 412, 414, 416, and418). Again, mobile device 202 maintains the low power state of its WLANtransceiver portion, despite mobile device 202 being within WWAN cell408 of the second WLAN having wireless AP 450.

FIG. 4 will now be described to illustrate the technique associated withthe flowchart of FIG. 3B. Mobile device 202 has a plurality of WLANprofiles stored in its memory, including the WLAN profile associatedwith the first WLAN having wireless AP 404. Mobile device 202 does nothave any stored WLAN profile or information for the second WLAN havingwireless AP 450. Having previously traversed this environment, mobiledevice 202 stores different sets of WWAN cell identifications (e.g. cellIDs) in association with different location identifiers, whichcorrespond to WLAN failure regions. In this example, mobile device 202stores a set of cell IDs corresponding to WWAN cells 420, 422, and 424in association with a WLAN failure and a location identifier.

Mobile device 202 is operating in a WWAN and has its WLAN transceiverportion in the low power state. When performing a WWAN scanningoperation in location J, mobile device 202 receives a current set ofcell IDs corresponding to WWAN cells 416 and 418. The comparison betweenthe current and stored sets of cell IDs results in a match of zero cellIDs (WWAN cells 416 and 418) out of the three cell IDs (WWAN cells 420,422, and 424), which is a 0% match. In this example, the predeterminedthreshold for WLAN operation is set at two (2) cell IDs or 50% (i.e. 2out of 4). As 0% is less than the predetermined threshold of 50%, thereis an increased probability that a WLAN will be found. In response, themobile device enables its WLAN transceiver portion and performs ascanning operation in attempt to identify the first WLAN correspondingto the stored WLAN profile. In this case, mobile device 202 is notlocated within the coverage region of wireless AP 404 of the first WLAN,and therefore is unable to connect. Thus, the mobile device 202continues to operate in the WWAN, and may continue to perform scanningoperations using its WLAN transceiver portion at this location.

Subsequently, moving to location K, mobile device 202 continues tooperate in the WWAN with its WLAN transceiver portion in the low powerstate. When performing a WWAN scanning operation in the location K,mobile device 202 receives a current set of cell IDs corresponding toWWAN cells 410, 412, 416, and 418. The comparison between the currentand stored sets of cell IDs results in a match of zero cell IDs (WWANcells 410, 416, and 418) out of the three cell IDs (WWAN cells 420, 422,and 424), which is again a 0% match. As 0% is less than thepredetermined threshold of 50%, the mobile device continues to performscanning operations in attempt to identify the first WLAN correspondingto its stored WLAN profile. In this case, mobile device 202 is notlocated within the coverage region of wireless AP 404 of the first WLAN,and therefore is unable to connect. Thus, the mobile device 202continues to operate in the WWAN, and may continue to perform scanningoperations using its WLAN transceiver portion at this location.

Later, moving to location L, mobile device 202 performs a WWAN scanningoperation and receives a current set of cell IDs corresponding to WWANcells 410, 412, and 418. The comparison between the current and storedsets of cell IDs again results in a match of zero cell IDs (WWAN cells410, 412, and 418) out of the three cell IDs (WWAN cells 420, 422, and424), which is still a 0% match. As 0% still fails to meet or exceed thepredetermined threshold of 50%, the mobile device enables its WLANtransceiver portion and performs a scanning operation in attempt toidentify the first WLAN corresponding to its stored WLAN profile. Inthis case, mobile device 202 is located within the coverage region ofwireless AP 404 of the first WLAN, and therefore is able to connect inthe WLAN. Thus, the mobile device 202 operates for communications in thefirst WLAN. In addition, the mobile device 202 may place its WWANtransceiver portion in the low power state if desired, or request andreceive only partial services from the WWAN (e.g. the remaining servicesbeing obtaining via the first WLAN).

Subsequently, moving to location M, mobile device 202 loses coveragewith the first WLAN and switches operation to the WWAN in response. Whenperforming a WWAN scanning operation in the location M, mobile device202 receives a current set of cell IDs corresponding to WWAN cells 410,414, and 424. The comparison between the current and stored sets of cellIDs results in a match of one cell ID (WWAN cell 424) out of the threecell IDs (WWAN cells 420, 422, and 424), which is a 33% match. As 33%still fails to meet or exceed the predetermined threshold of 50%, themobile device enables its WLAN transceiver portion and performs ascanning operation in attempt to identify the first WLAN correspondingto its stored WLAN profile. In this case, mobile device 202 is notlocated within the coverage region of wireless AP 404 of the first WLAN,and therefore is unable to connect. Thus, the mobile device 202continues to operate in the WWAN, and may continue to perform scanningoperations using its WLAN transceiver portion in attempt to identify thefirst WLAN.

Moving to location N, mobile device 202 performs a WWAN scanningoperation and receives a current set of cell IDs corresponding to WWANcells 420, 422, and 424. The comparison between the current and storedsets of cell IDs results in a match of three cell IDs (WWAN cells 420,422, and 424) out of the three cell IDs (WWAN cells 420, 422, and 424),which is a 100% match. As 100% exceeds the predetermined threshold of50%, mobile device 202 sets and maintains its WLAN transceiver portionin the low power state, and maintains operation in the WWAN. At locationP, mobile device 202 receives a current set of cell IDs corresponding toWWAN cells 414, 422 and 424, resulting in a 66% match of two cell IDs(WWAN cells 422 and 424) out of the three cell IDs (WWAN cells 420, 422,and 424). Again, mobile device 202 maintains the low power state of itsWLAN transceiver portion, despite mobile device 202 being within WLANcell 408 of the second WLAN having wireless AP 450.

FIGS. 5, 6A, and 6B are flowcharts for describing a more detailed methodrelated to the technique of FIG. 3A for controlling transceiveroperation of the mobile device. The mobile communication device may bethat which has been shown and described earlier in relation to FIG. 1 or2, making use of one or more controllers or processors (e.g.microprocessor) to perform the techniques. The technique of FIGS. 5, 6A,and 6B may be embodied as a computer program product which includes acomputer readable medium (e.g. memory or computer disk) and computerinstructions stored in the computer readable medium. The computerinstructions are executable by the one or more controllers or processorsof a mobile device and adapted in accordance with the described steps orlogic.

The technique refers to WLAN cells associated with WLANs having storedWLAN profiles. The mobile device is initially operating in a WWAN forcommunications, and has its WLAN transceiver portion in the low powerstate. Beginning at a start block 502 of FIG. 5, the mobile devicedetects or otherwise identifies whether it has undergone a change inlocation or other condition (step 504 of FIG. 5). If not, the mobiledevice continues to monitor for such condition. If the mobile devicedetects such condition in step 504, the mobile device identifies whetherit is connected in a WLAN cell of one of the WLANs with which it has astored WLAN profile (step 506 of FIG. 5). If connected in a WLAN cell,the mobile device updates its WLAN cell profile with any cell IDs ofWWANs not already included in the WLAN profile (step 508 of FIG. 5). Ifnot connected in any WLAN cell in step 506, the mobile device identifieswhether any stored WLAN profile has a probability to be found that meetsor exceeds a threshold (step 510 of FIG. 5). The probability to be foundis based on the number or percentage of current WWAN cells that matchthe cell IDs stored in association with the home cell profile. If no instep 510, then the mobile device continues back at step 504.

If the probability exceeds the threshold in step 510, the mobile deviceenables its WLAN transceiver portion (if previously disabled) and causesone or more scanning operations to be performed with use of its WLANtransceiver portion (step 512 of FIG. 5). The mobile device performsthis step to identify the WLAN which has the increased probability ofbeing found. If the mobile device identifies the WLAN (step 514 of FIG.5), the mobile device connects with it for communications and updatesits WLAN profile with any cell IDs of WWANs not already included in thecorresponding WLAN profile (step 508 of FIG. 5).

If the mobile device does not identify and connect with the WLAN in step514, then the mobile device identifies whether it has changed itslocation (step 516 of FIG. 5). If the mobile device has not changedlocation as identified in step 516, the mobile device repeats the WLANscanning operation at step 512; otherwise, the mobile device exits WLANscanning and repeats processing steps of the flowchart starting again atstep 510 where the probabilities of finding WLANs are reevaluated. Notethat the mobile device may perform the WLAN scanning step 512 only forWLANs associated with the increased probability to be found (i.e. andnot other WLANs not having the increased probability).

FIGS. 6A-6B is a flowchart for describing part of the method which maybe performed in parallel with the method of FIG. 5. Beginning at a startblock 602 of FIG. 6A, the mobile device performs a WWAN scanningoperation, obtains WWAN cell identifications from the scanningoperation, and moves and operates in one of the WWAN cells in the WWAN(step 604 of FIG. 6A). The mobile device takes a signal measurement(e.g. signal strength, or received signal strength indication “RSSI”)for each cell. Based on this information, the mobile device creates andstores a list of “m” WWAN cells identifications, which include the WWANserving cell and neighboring WWAN cell identifications, in descendingorder of signal strength (step 606 of FIG. 6A). In one embodiment, themobile device includes a received cell identification in the list onlyif its corresponding cell has a signal strength that meets or exceeds apredetermined signal strength threshold, but otherwise excludes thereceived cell identification from the list.

The mobile device then identifies whether it is connected in a WLAN cell(i.e. one of its WLANs) (step 608 of FIG. 6A). If the mobile device isconnected in a WLAN cell in step 608, the mobile device identifieswhether the WLAN profile of the connected WLAN cell includes the servingcell ID of the WWAN serving cell (step 640 of FIG. 6A). If not, then themobile device adds the serving cell ID of the serving cell to the WLANprofile (step 642 of FIG. 6A). If the serving cell ID is alreadyincluded in the WLAN profile in step 640, or after step 642 isperformed, the flowchart ends at an end block 644.

If the mobile device is not connected in a WLAN cell in step 608, themobile device proceeds through a connector A to FIG. 6B and performs aseries of steps for each one of a plurality of “t” WLAN profiles storedin its memory. Each series of steps for each WLAN profile may beperformed in parallel or in series; in FIG. 6B, each series of steps isshown as being performed in parallel with the others. In particular, aseries of steps 610, 612, 614, and 616 is performed for WLAN profile 1;a series of steps 620, 622, 624, and 626 is performed for WLAN profile2; and so on, where a series of steps 630, 632, 634, and 636 isperformed for WLAN profile t.

With respect to WLAN profile 1, beginning at step 610, the mobile devicedetermines whether the number of matching WWAN cells in the list (i.e.the “current set”) and the WLAN profile meets or exceeds a predeterminedthreshold “n”. If not, the flowchart proceeds through a connector C backto FIG. 6A at end block 644. If the number of matching WWAN cells meetsor exceeds the predetermined threshold n in step 610, the mobile deviceconfigures the scanning pattern for WLAN 1 (step 612 of FIG. 6B). Themobile device scans for WLAN 1 based on the information in the WLANprofile 1 (step 614 of FIG. 6B). If WLAN 1 is identified and available(step 616 of FIG. 6B), then the flowchart proceeds through a connector Bback to FIG. 6A to step 640. If not, the mobile device continues tomonitor to identify the availability of WLAN 1. As described earlier,the same series of steps are performed in steps 620, 622, 624, and 626in relation to WLAN 2 and WLAN profile 2; and the same series of stepsare performed in steps 630, 632, 634, and 636 in relation to WLAN t andWLAN profile t.

Another illustrative example of the techniques as described in relationto FIGS. 3A, 5, and 6A-6B is now set forth in relation to FIGS. 7-14.FIG. 7 is a map of a geographic region 700 within which mobile device202 may traverse during its operation. Geographic region 700 identifiesvarious locations 702, 704, and 706 within a few square blocks. At thestreet intersection of Wiggins Pvt. and Nancy Smith Pvt., i.e. location706, a residence is located, which is depicted as residence 850 in FIG.8.

In FIG. 8, it is revealed that residence 850 has a kitchen room/area802, a bedroom area 804, a living room/area 806, and a master bedroomarea 808. Kitchen area 802 includes a wireless AP 810 of a WLAN in whichmobile device 202 is adapted to operate. Wireless coverage forcommunication is provided by wireless AP 810 in all areas 802, 804, 806,and 808.

However, especially as areas of residence 850 are facing different sidesof the building, different WWAN cells of base stations are received ineach different area 802, 804, 806, and 808. To illustrate, each figurein FIGS. 9-14 reveals cell information received by the mobile devicefrom a WWAN scanning operation while traversing geographic region 700 ofFIG. 7 and the various areas 802, 804, 806, and 808 within residence 850of FIG. 8. More specifically, the cell information in FIGS. 9-14corresponds to the following:

FIG. 9—kitchen area 802

FIG. 10—bedroom area 804

FIG. 11—living area 806

FIG. 12—master bedroom 808

FIG. 13—location 704, outside of residence 850

FIG. 14—location 706, outside of residence 850

As apparent from FIGS. 9-14, the WWAN serving cell (“S” in the figures)of mobile device 202 and the WWAN neighboring cells (“E” or “G” in thefigures) change depending on which area of residence 850 the mobiledevice 202 is located.

The cell information shown in FIGS. 9-14 includes various other data. InFIG. 9, for example, the “best” WWAN cell which serves mobile device 202in kitchen area 802 corresponds to a base station having an absoluteradio frequency channel number (ARFCN) or “frequency” of 140, a radiosignal strength indication (RSSI) of −86 dBm, and a cell ID of 34093.The serving base station is identified with other information, such as apath loss criterion C1 of 22, a cell reselection criterion C2 of 26, abase station identity code (BSIC) of 12, and a routing area code (RAC)of 1.

With use of the present techniques, the stored set of cell IDsassociated with the WLAN profile may be set with the following five (5)cell IDs:

Cell ID 34093 (serving cell in kitchen area 802), ARFCN 140

Cell ID 33992 (serving cell in bedroom area 804), ARFCN 137

Cell ID 33993 (serving cell in living area 806), ARFCN 134

Cell ID 23533 (serving cell in master bedroom 808), ARFCN 143

Cell ID 34103 (a relatively strong cell in general), ARFCN 136

Based on this stored set associated with the WLAN profile, the typicalnumber of matching WWAN cells in each given area and the resulting WLANoperation state may be as follows:

Kitchen Area 802=4/5 WWAN cells=enable WLAN operation

Bedroom Area 804=5/5 WWAN cells=enable WLAN operation

Living Area 806=3/5 WWAN cells=enable WLAN operation

Bedroom Area 808=3/5 WWAN cells=enable WLAN operation

Location 706=3/5 WWAN cells=enable WLAN operation

Location 708=1/5 WWAN cells=disable WLAN operation

where the predetermined threshold may be set at 60%, for example.

As apparent from the present techniques, since the WLAN transceiverportion need not be rigorously operated for scanning, enabled, oractivated while WWAN communications take place, unnecessary operationsare avoided. In addition, power consumption may be reduced and batterylife may be increased.

Thus, methods and apparatus for use in controlling wireless transceiveroperation in a mobile communication device which is adapted to operatefor communications in WWAN and WLAN have been described. In oneillustrative embodiment, the mobile device operates for communicationsvia the WLAN with use of a WLAN transceiver portion. During suchoperation, the mobile device performs one or more scanning operationswith use of a WWAN transceiver portion for identifying a set of cellsite identifications corresponding to a plurality of base stations ofone or more WWANs available in a coverage region of the WLAN. The set ofcell site identifications is stored in association with a WLAN profileof the WLAN. Subsequently, while the mobile device operates forcommunications in a WWAN, the WLAN transceiver portion may be maintainedin a low power state. During the WWAN operation, the mobile deviceperforms one or more scanning operations with use of the WWANtransceiver portion for identifying a current set of cell siteidentifications corresponding to the currently-serving base station ofthe WWAN and one or more neighboring base stations. The mobile devicecompares cell site identifications of the current set with cell siteidentifications of the stored set, and identifies if the number orpercentage of matching cell site identifications of the current andstored sets meets or exceeds a predetermined threshold. If thepredetermined threshold is met or exceeded, the mobile device enablesoperation of the WLAN transceiver portion for communications via theWLAN; otherwise, the mobile device refrains from enabling operation ofthe WLAN transceiver portion for communications via the WLAN. Thistechnique may be performed in association with each WLAN profile storedin the mobile device.

In another illustrative embodiment, the mobile device performs one ormore scanning operations with use of the WLAN transceiver portion in ageographical region, but fails to connect with any WLANs in thegeographical region. The mobile device also performs one or morescanning operations with use of the WWAN transceiver portion foridentifying a set of cell site identifications corresponding to aplurality of base stations of one or more WWANs available in thegeographical region. The set of cell site identifications is stored inassociation with an indication of the failure to connect with any WLANsin the geographic region. Subsequently, while operating forcommunications via a WWAN with use of the WWAN transceiver portion, theWLAN transceiver portion may be maintained in a low power state. Duringthe WWAN operation, the mobile device performs one or more scanningoperations with use of the WWAN transceiver portion for identifying acurrent set of cell site identifications. The current set of cell siteidentifications corresponds to the currently-serving base station of theWWAN and one or more neighboring base stations. The mobile devicecompares cell site identifications of the current set with cell siteidentifications of the stored set. If the mobile device identifies apredetermined condition where the number or percentage of matching cellsite identifications of the current and stored sets meets or exceeds apredetermined threshold, it refrains from enabling operation of the WLANtransceiver portion for communications in a WLAN. This technique may beperformed in association with each one of a plurality of geographicregions through which the mobile device traverses.

Although the detailed description focuses on the use of two specificnetworks (namely a cellular network as the WWAN and an IEEE 802.11network as the WLAN), any two suitable heterogeneous networks may beutilized, where one of the networks has overlapping coverage with or iscontained within the other network. For example, the WLAN may be an IEEE802.11-based network and the WWAN may be an IEEE 802.16e-based network.As another example, the WLAN may be an IEEE 802.16e-based network andthe WWAN may be the cellular network. Home Node-B cells of a 3G macroRadio Access Network (RAN) may be also utilized with cellular, IEEE802.11, or IEEE 802.16 technologies in the same fashion. As apparent,the above-described embodiments of the present application are intendedto be examples only. Those of skill in the art may effect alterations,modifications and variations to the embodiments without departing fromthe scope of the application.

The invention claimed is:
 1. A method in a mobile communication devicefor communications, the method comprising: performing one or morescanning operations with use of a first transceiver portion in ageographical region; failing to connect with any first wireless networksin the geographical region; performing one or more scanning operationswith use of a second transceiver portion for identifying a set of cellidentifications corresponding to a plurality of stations of one or moresecond wireless networks available in the geographical region; storingthe set of cell identifications in association with an indication of thefailure to connect with any first wireless networks in the geographicregion; while operating for communications via a second wireless networkwith use of the second transceiver portion: performing one or morescanning operations with use of the second transceiver portion foridentifying a current set of cell identifications, the current set ofcell identifications corresponding to a currently-serving station of thesecond wireless network and one or more neighboring stations; comparingcell identifications of the current set with cell identifications of thestored set; and when the number or percentage of matching cellidentifications of the current and stored sets meets or exceeds apredetermined threshold, setting the first transceiver portion in a lowpower state.
 2. The method of claim 1, further comprising: otherwise,when the number or the percentage of the matching cell siteidentifications of the current and stored sets fails to meet or exceedthe predetermined threshold, maintaining the first transceiver portionin an enabled state of operation.
 3. The method of claim 1, wherein thefirst transceiver portion is operative in accordance with IEEE 802.11standards.
 4. The method of claim 1, wherein the second transceiverportion comprises a cellular transceiver.
 5. The method of claim 1,further comprising: storing the set of cell identifications in a profileof the first wireless network, the profile including the identificationof the first wireless network.
 6. The method of claim 1, furthercomprising: when the number or the percentage of matching cell siteidentifications of the current and stored sets fails to meet or exceedthe predetermined threshold, increasing a scanning rate for performingscanning operations with use of the first transceiver portion.
 7. Themethod of claim 1, further comprising: when the number or the percentageof matching cell site identifications of the current and stored setsmeets or exceeds the predetermined threshold, refraining from enablingoperation of the first transceiver portion for communications.
 8. Themethod of claim 1, further comprising: again performing one or morescanning operations with use of the first transceiver portion in anothergeographical region; failing to connect with any first wireless networksin the other geographical region; and updating the stored set of cellsite identifications with one or more newly-identified cell siteidentifications corresponding to one or more newly-identified stationsin association with the indication of the failure to connect with anyfirst wireless networks in the other geographical region.
 9. The methodof claim 1 wherein the predetermined threshold is set to represent lessthan the number of the cell site identifications in the stored set. 10.The method of claim 1, implemented as a computer program productcomprising a non-transitory computer readable medium having computerinstructions executable on one or more processors of the mobilecommunication device.
 11. A mobile communication device, comprising: afirst transceiver portion configured to operate for communications withone or more first wireless networks; a second transceiver portionconfigured to operate for communications with one or more secondwireless networks; one or more processors coupled to the first and thesecond transceiver portions; memory coupled to the one or moreprocessors; the one or more processors being operative to: perform oneor more scanning operations with use of a first transceiver portion in ageographical region; fail to connect with any first wireless networks inthe geographical region; perform one or more scanning operations withuse of a second transceiver portion for identifying a set of cellidentifications corresponding to a plurality of stations of one or moresecond wireless networks available in the geographical region; store theset of cell identifications in association with an indication of thefailure to connect with any first wireless networks in the geographicregion; while operating for communications via a second wireless networkwith use of the second transceiver portion: perform one or more scanningoperations with use of the second transceiver portion for identifying acurrent set of cell identifications, the current set of cellidentifications corresponding to a currently-serving station of thesecond wireless network and one or more neighboring stations; comparecell identifications of the current set with cell identifications of thestored set; and when the number or percentage of matching cellidentifications of the current and stored sets meets or exceeds apredetermined threshold, set the first transceiver portion in a lowpower state.
 12. The mobile communication device of claim 11, whereinthe one or more processors are further operative to: when the number orthe percentage of the matching cell site identifications of the currentand stored sets fails to meet or exceed the predetermined threshold,maintain the first transceiver portion in an enabled state of operation.13. The mobile communication device of claim 11, wherein the firsttransceiver portion is operative in accordance with IEEE 802.11standards.
 14. The mobile communication device of claim 11, wherein thesecond transceiver portion comprises a cellular transceiver.
 15. Themobile communication device of claim 11, wherein the one or moreprocessors are further operative to: store the set of cellidentifications in a profile of the first wireless network, the profileincluding the identification of the first wireless network.
 16. Themobile communication device of claim 11, wherein the one or moreprocessors are further operative to: when the number or the percentageof matching cell site identifications of the current and stored setsfails to meet or exceed the predetermined threshold, increasing ascanning rate for performing scanning operations with use of the firsttransceiver portion.
 17. The mobile communication device of claim 11,wherein the one or more processors are further operative to: when thenumber or the percentage of matching cell site identifications of thecurrent and stored sets fails to meets or exceeds the predeterminedthreshold, refrain from enabling operation of the first transceiverportion for communications.
 18. The mobile communication device of claim11, wherein the one or more processors are further operative to: againperform one or more scanning operations with use of the firsttransceiver portion in another geographical region; fail to connect withany first wireless networks in the other geographical region; and updatethe stored set of cell site identifications with one or morenewly-identified cell site identifications corresponding to one or morenewly-identified stations in association with the indication of thefailure to connect with any first wireless networks in the othergeographical region.
 19. The mobile communication device of claim 11,wherein the predetermined threshold is set to represent less than thenumber of the cell site identifications in the stored set.
 20. Acommunication system, comprising: a first wireless network; one or moresecond wireless networks; one or more mobile communication devicesconfigured to operate for communications; each mobile communicationdevice being operative to: perform one or more scanning operations withuse of a first transceiver portion in a geographical region; fail toconnect with any first wireless networks in the geographical region;perform one or more scanning operations with use of a second transceiverportion for identifying a set of cell identifications corresponding to aplurality of stations of one or more second wireless networks availablein the geographical region; store the set of cell identifications inassociation with an indication of the failure to connect with any firstwireless networks in the geographic region; while operating forcommunications via a second wireless network with use of the secondtransceiver portion: perform one or more scanning operations with use ofthe second transceiver portion for identifying a current set of cellidentifications, the current set of cell identifications correspondingto a currently-serving station of the second wireless network and one ormore neighboring stations; compare cell identifications of the currentset with cell identifications of the stored set; and when the number orpercentage of matching cell identifications of the current and storedsets meets or exceeds a predetermined threshold, set the firsttransceiver portion in a low power state.